1. Field of the Invention
The present invention relates to a grommet. The grommet of the present invention is particularly useful in a network interface device in which a plurality of wires or cables enter an enclosure.
2. Description of the Prior Art
Historically grommets useful in network interface devices have been fabricated from a homogeneous, flexible rubber-like material. Such grommets typically include a center section in the form of a single membrane through which one or more wires, cables or conduits and the like, referred to herein as "wires", enter or exit the device, and a thicker outer peripheral section which may be attached to an apertured surface of the device in the usual manner. In order to insert such wires into the device, typically the membrane is punctured or slit. For example, in some prior art grommets, the thin membrane which forms the center section is punctured to provide a hole through which the wires may be inserted or threaded directly through the grommet and into the device. In other prior art grommets, it is desirable to slit the grommet from the center of the membrane completely through the generally thicker outer peripheral section thereby permitting the wires to be dropped into the grommet in a generally radial direction as opposed to threaded through a hole in the grommet center.
In order to facilitate and direct the tearing or otherwise opening of the grommet material, it is common for the center section to be thin relative to the outer peripheral section. It is also common to provide the center section with a pre-creased pattern. When the term "pre-creased pattern" is used herein it is meant that the membrane has been provided with means to facilitate and direct the tearing or otherwise opening of the membrane in the desired pattern. For example, the membrane surface may be provided with thinner sections which coincide with a desired pattern. In another example, the membrane surface may be scored by providing lines, grooves, notches and the like which outline the desired pattern. In yet another example, the membrane may be provided with apertures or slits which define the desired pattern.
Some patterns are known to be preferable over others depending upon the application. Patterns in the form of thin circular areas are typical in applications where a single wire is to be pushed through the grommet. When a plurality of wires having varying sizes are to be inserted into the device, a star shaped pattern is desirable. It is common for the pattern to be the same on one or both surfaces of the membrane thus providing grommets for a specific end use.
Typically the center section of prior art grommets is thin in order to facilitate the puncturing, slitting or tearing thereof as described above, and also so that the membrane will be compliant. In theory, the punctured membrane acts as a sphincter around a single wire, conduit or cable passing through the membrane to provide a tight fit to prevent moisture, dust or insects from entering the enclosure. However, in many enclosures such as, for example, typical network interface devices, a plurality of wires pass through the grommet. The result is that open air spaces exist around the wires due to the inability of the grommet to conform exactly to the irregular shape which is present.
It is an object of the present invention to provide an improved grommet having a central section which will conform to one or more wires which pass through the grommet.
A further object of the present invention is to provide such a grommet wherein one or more wires may be inserted directly through the center section of the grommet.
Another object of the present invention is to provide such a grommet wherein one or more wires may be dropped into the grommet in a generally radial direction.
Yet a further object of the present invention is to provide such a grommet having a plurality of distinct patterns for varying applications.
Another object of the present invention is to provide such a grommet having a plurality of distinct patterns for varying applications, the patterns being disposed in such a manner that puncturing and tearing of the grommet is facilitated.